This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The purpose of this study is to demonstrate Fluorescent modulated imaging (fMI) via the quantitative and qualitative measurement of fluorophore phantoms. Fluorescent perturbations with various spatial and depth profiles in phantoms will be investigated. Qualititatively, the ability for spatial localization of the fluorophore. Quantitatively, the ability to measure fluorophore concentration as well as concentration and pH independent fluorophore metrics such as quantum yield will be investigated. Finally, tomographic reconstruction algorithms will be developed in parallel.